Fire-alarm system.



E. SCHUMANN.

FIRE ALARM SYSTLM.

APPLICATION FILED JUNE 2a, 1913.

1,105,044, Patented July 28, 1914.

UNITED s'ra'rns PATENT OFFICE.-

ERNST SCHUMANN, OF CHABLOTTENBURG, GERMANY, ASSI IGNOR TO SIEMENS & HALSKE, A. 6., O BERLIN, GERMANY, A CORPORATION OF GERMANY.

FIRE-ALARM SYSTEM.

Specification of Letters Patent.

Patented July 28, 1914.

Application filed June 28, 1913. Serial No. 776,278.

To all whom it may concern:

Be it known that I, Eimsr SCIIUMANN, a citizen of the German Empire, and residin at Charlottenburg, Germany, have invente certain new and useful Improvements in Fireullarm Systems, of which the followingvlis a specification.

tems in which a ground connection is rovided for working when the line is bro (on.

In fire-alarm systems wherein the various alarms are connected in series in each circult, apparatus has been devised both for rounding the alarm when the alarm-signal is given and also for establishing a ground connection at the receiving station when a breakage occurs in'the line forming the circuit, so that in the event of a wire being broken the currents flowing in the portions of the circuit on both sides of the breakage find a path through ground and in this manner enable lhc alarm to be given. In such systems dilliculties are met with in employing those. known devices for nongrounded circuits which are intended to prevent confusion in the signals when several alarms are Slllllllt-HllQOuSly set into operation. The reason for this is that when employing the known devices in such a. case, the alarms which are pulled would be simultaneously put to ground and consequently the remaining portion of the circuits which is beyond these alarms would become shortcircuited.

primary object of my invention is to obviate this defect. To this end 1 make the connection to ground dependent on a contact member which when the alarm is given makes contact to ground only as the result of the principal magnet not. attracting its armature owing to a breakage of the wire or the like, but at other times keeis the ground circuit open. In addition, associate with each alarm a magnet having scv cral windings or several magnets which, when once the ground connection is made at an alarm, maintains this connection until the broken .wire is repaired, or until another part of the circuit grounded, in which use the alarm in question is located in a closed circuit.

One embodiment of my invcntiou dim grammatically illustrated by way of example in the accompanying drawing show invention relates to firealarm Sy ing a circuit containing a, number of alarms of which one is shown in retail in elevation.

Referring to the drawing the various alarms M to M, are located in the circuit 1. At the receiving station E the usual relays 3, resistances 3, measuring instruments 4 and the like are provided, and also the buttery B, whose middle point is connected to ground by a lead 5 in the event of a. breakage of wire. In each of the alarms the circuitn'heel 7, which influences a contact-spring 6, is rigidly connected'with a controlling disk 8 and is driven by means of intermediate gears 9 by driving mechanism 10, which is released upon depressing a key 11. \Vhen this key is depressed a spring-pulled lever 16 fulcrumed on the axle 15 is released ow ing to a stop 14 provided thereon being released by the catch 13, on the key-lever 11 and consequently moves upward under the influence of'its spring 17. A stop 18 on the lever 16 has a right angled extension, the said extension lying in a plane parallel to the plane of the p1nf19 and engaging said pin. Consequently a.downward movement of the lever 16 releases the said pin 19 which is mounted on the wheel 20 driving the fly 21. This serves as the lock for the mechanism 10. The circuit-wheel 7 thereupon begins to rotate in the direction indicatcd by the arrow. At the same time the. lever 16 being in engagement with a lever 25 fulcrumed on the axle 24 by means of :1 lug 25 provided thereon. drives upward the one end of said second lever 25, Without however making the round contact 26' which is influenced by t 1e other end of this lever, because a resilient stop 12 first of all checks further movement.

When the circuit 1- is unbroken throughout owing to the depression of the key 11 the contact 27 bridging the alarm is opened by a projecting lug 11 on the key-lever 11 and held open by a catch 37' fulcrumed on a two-armed lever 37 and the following circuit is formed: battery B, at the receiving station E. right half of loop 1, magnet 28 in alarm M righbhand winding of another magnet 29, interrupter contact-piece 30 of the contact-spring 6 set into motion by the rotation of the circuit-wheel 7, left-hand winding of the magnet 29, another magnet 42, and back over the left half of the circuit to the battery 13,. The magnet 29 attracts spring 12'. Llfhe type-wheel and the met-ha nism geared thereto cannow continue to rotate without hindrance until finally a eurolike projection 35 on the controlling disk 8, after making one revolution, drives the lever 34 aside and consequently releases the lever 16 from the detent The latter lever then returns into its normal position where it is held by the catch 13 provided on the key-lever 11, and consequently its stop 18 arrests the driving mechanism ll) by stopping the pin 19. Just before this occurs, a cam-like projection 36also on the controlling disk 8 has rocked overthe two-armed lever 37 and disengaged the catch 37 connected to this lever from one of the contact members 27, so that the bridging contact 27 can return into its normal position and the alarm is againshort-circuited.

During the continuance both of the closed-circuit current as well as of the alarm current themagnets 28 and 42 remain ener- 'gized, so that their armatures 38 and 39 are attracted and cannot hold the grounding lever 25 at its ends 40, 40' adapted to coact with these armatures. On the other hand, the conditions are different when a breakage occurs in the line. Assuming, for example, that such a breakage occrirs in the right half of the circuit, say at a point A, and that the alarm M, is subsequently operated by depressing the key 11, the bridging contact 27 would again be opened, but the armature 31 of the magnet 29 would not be attracted, so that the lever 16 under the influence of the spring 17 and, consequently, the grounding lever 25 would remain in their raised positions. In this position a pin 43 extending backward in a direction normal to the plane of the drawing projects into a notch 41 in a circular collar 44 on the circuit-wheel or the controlling disk, As soon however as the alarm has moved a short distance a slanting face 45 on the circular collar bears against the pin 43 and compels the latter to overcome the pressure of the resilient stop 12 and to enter the track or way 46, the lever 25 being thus rocked still further and making the ground-contact 26 by means of its lug 25", so that the alarm is grounded for the continuance of the rotation of the circuit-wheel. The circuit now closed is as follows: battery 13,, conductor 5, ground, contact 26, binding post 47 of the contactspring (3 moved by the circuit-wheel, contact-piece 30, left-hand winding of'magnet 29, magnet 42, left half of the circuit, and

signal is delivered in the normal rescuer;

Owing to the magnet 28 being cnrreniiicse the ground connection is maint. the driving mechanism has run down. so that each new alarm is effected without ditlicult, by passing over ground. 'ihe Shi l ground connection iodisconn" ionl hen the magnet 28 again receives tfliil'ltli cby attracting its armature 38 and releasing the groundin lever :35. This occurs either when the bro en wire is re aired, or when an alarm in series with the a arm in question is required to deliver an alarm signal and is grounded in a me nner corresponding to that described, For example, lithe key of the alarm ll i, were depressed a Z lib: i M, were grounded owing to ores at 5., its ma ,riet would of all. he current less. 3 soon. as the key o an charm M, located beyond is depressed, wever, the

magnet just referred to obtains over the ground contact of this alerin a current, and so automatically disconnectsits own ground connection. The same occurs if, for cxample, the line is grounded at the broken place. If the breakage is located in the'left half of the circuit, 2. g. atthe point B, the

circuit of the battery B, is closed over ground, contact 26, binding post =27, contact-- spring (3, right-hand winding ofinagnet- 2S), and magnet 28. The magnet 42 therefore remains unenergized and now in turn holds down the grounding lever 25 owing to its armature 39 keeping down the stop 40. The two magnets 28 and -l2 may be united to form one magnet having two indings, its armature for influencing the grounding lever being attracted only when current flows through both windings. in a similar way this magnet may be united with the magnet 29.

1 In a fire-alarm system, the combination of a circuit including a circuit-brealer and. an electromagnet; a normally open switch for connecting said circuit to ound, grounding member for closing said switch, automatic mechanism for actuating said circuit-breaker and driving said grounding member and thereby closing said switch, releasing means for releasing said automatic mechanism and drivin the said groundin member into an operat ve position in which it can be driven by the automatic mechanism led after ice and thereby elose'said switch, and retracting means controlled by said eleetromagnet for preventing said releasing means driving said grounding member into said operative position.

2. In a fire-alarm system, the combination of a circuit including a circuit-breaker, a main eleetromagnet and two auxiliary electromagents in series therewith; a normally open switch for connecting said circuit to ground, a grounding member for closing said switch, the unattracted armatures of the auxiliary eleetromagnets bein adapted to hold the grounding member in its switchclosing position, automatic mechanism for actuating said circuit-breaker and driving said grounding member and thereby closing said switch, releasing means for releasing said automatic mechanism and driving the said grounding member into an operative position in which it can be driven by the automatic mechanism and thereby close said switch, and retracting means controlled by said electromagnet for prcventin said releasing means drivihg said groun ing member into said erative position.

3. In a fire-a arm system, the combination of a circuit including a main eleetromagnet comprising two windings, a circuit breaker connected between the two windings to the one end thereof and two auxiliary electromagnets connected in-serics with the windings to the other ends thereof; a normally open switch for connecting said circuit to ground, a grounding member for closing said switch, the unattraeted armatures of the auxiliary electromagnets being adapted to hold the grounding member in its switchelosing position, automatic mechanism for actuating said circuit-breaker and driving said grounding member and thereby closing said switch, releasing means for releasing said automatic mechanism and driving the said grounding member into an operative position in which it can be driven by the automatic mechanism and thereby close said sw 'ch, and retracting means controlled by sain electromagnet for preventing said releasing means driving said grounding member into said operative position.

4. In. a fire-alarm system. the combination of a circuit including a main electromagnet comprising two windings, a circuit-breaker connected between the two windings to the one end thereof and two auxiliary electromagnets connected in series with the windings to the other ends thereof: a normally open-switch for connecting said circuit to ground, a grounding member for closing said switch, the unattracted armatures of the auxiliary eleetromagnets being adapted to hold the grounding member in its switchclosing position, automatic mechanism for actuating said circuit-breaker and driving said grounding member and thereby closing said switch, a. short-circuiting switch normally short-cireuitingthe main electromagnet and circuit-breaker, arresting means for arresting the short-circuiting switch in its open position, releasing means for opening the short-eircuiting switch, releasing said automatic mechanism and driving the said grounding member into an operative position in which it can be driven by the automatic mechanism and thereby close said former switch, and retracting means controlled by said electromagnet for preventing said releasing means driving said grounding member into said operative position.

5. In a firealarm system, the combination of a circuit including a circuit-breaker, a main electromagnet and two auxiliary electromagnets in series therewith; a normally open grounded switch electrically connected with the circuit-breaker. a spring-influenced grounding lever for closing said switch. each armature of the auxiliary electromagnets being adapted to hold said lever in its switchelosing position; automatic mechanism for actuating said circuit-breaker and driving said lever and thereby closing said switch a short-eircuiting switch normally short-01rcuiting the main electromagnet and circuitbreaker, a catch adapted to be released by the automatic mechanism for holding the short-cir uitiug switch in its open position, a spring-influenced releasing lever normalldy coaeting with the grounding lever and ten ing to drive the same into engagement with the automatic mechanism, a-s'top on the releasing lcver for arresting the automatic mechanism in the rest-position of tho, releasin lever, a key-lever normally holding the re easing lever in its rest position and adapted to open said short-cireuiting switch, and a. lever-arm controlled by the armature of the main electromagnet for driving the releasing lever into its lowest position.

In testimony whereof, I have signed my name to this specification in the presence of two witnesses.

ERNST SCHUMANN.

Witnesses HENRY HASPER, \Vonneira a H auv'r. 

